WiMAX, or WiMAX-I, is based on the IEEE (Institute of Electrical and Electronics Engineers) 802.16e standard. WiMAX-I employs orthogonal frequency division multiple access (OFDMA) for transmissions, resulting in improved multi-path performance in non-line-of-sight environments. WiMAX-I may employ single-user (SU) or multiple-user (MU) multiple-input multiple output (MIMO) antenna techniques, adaptive modulation and coding schemes, and flexible subchannelization. A new generation of WiMAX termed 802.16m is currently under development for broadband wireless access systems.